Evaluation Of Bunch Length By Measuring Coherent Synchrotron Radiation With A Narrow-Band Detector At Lebra

This study presents a novel technology to measure electron bunch length with a high time resolution by measuring coherent synchrotron radiation using a narrow-band detector at Laboratory for Electron Beam Research and Application (LEBRA)-an S-band linear accelerator facility for free-electron lasers. The form factor was observed to decrease exponentially with charge-in concordance with the relationship between the intensity of the coherent synchrotron radiation and the magnitude of electron bunch charge-in the region in which the effect of electron bunch charge on bunch length is negligible. The calculated root-mean-square bunch length was observed to agree well with the value determined from the spectral shape obtained. The aforementioned results are expected to be useful in real-time observation of small changes in electron bunches in advanced accelerators.